SECRETORY IMMUNOGLOBULIN A

Secretory Immunoglobulin A (sIgA) is the dominant antibody in bodily secretions and acts as a first line of defence against microbial invasion. sIgA levels are altered under the influence of stress hormones such as cortisol and in various emotional states and moods.

The stress hormone cortisol is the body’s main anti-inflammatory hormone and chronic stress leads to lowered sIgA and hence lowered immunity.